1. Field of the Invention
This invention relates generally to a soffit ventilation system which provides for proper venting of a building having an attic, prevents insects and environmental elements, such as water and snow, from entering the attic through the ventilator and can be tailor-made to a variety of pre-existing and newly constructed buildings.
2. Reported Developments
Soffit ventilators are perforated, louvered or baffled vent openings in the underside of the eaves of an overhanging roof or the facia covering the ends of roof rafters when the roof has no soffit or has very narrow soffit. The vent openings allow outside air to flow into the attic to equalize the interior attic temperature and pressure with that of the outside environment. This equalization helps to prevent degradation of the roof structure, reduces the accumulation of condensation in the insulating material covering the floor of the attic thereby increasing the efficacy of heating/cooling of the living space in the building covered by the roof structure.
The soffit ventilator system of the prior art is typically used in conjunction with a roof ridge ventilator overlying the open roof along the length of the roof for exhausting the air from the space below the roof and the ceiling of the attic, i.e., as the air entering the attic through the soffit vent mixes with the warmer air in the attic, it has to be expelled through an opening in the roof ridge where the lighter, warmer air accumulates. Desirably, the volume of air intake through the soffit ventilator should be balanced by the volume of air exhaust through the roof ridge ventilator. In an optimum soffit ventilator/roof ridge ventilator system there is a balance between the net free open area presented by such system. The terminology "Net Free Open Area" or NFA means the cross-sectional area of a ventilator system which is open for passage of air therethrough. This balance of the net free open area of a soffit ventilator and roof ridge ventilator is difficult to achieve. Thus in many existing and newly built buildings there tend to be an out of balance soffit/roof ridge ventilation system.
Ventilation systems should also provide against insects entering into the attic space of buildings. While large perforations in the soffit and roof ridge ventilation panels would render the desired flow of air through the attic space, they would also allow ingress to insects therein to form insect colonies. Insects typically enter into the attic through the soffit vents. The prior art for this and other reasons provides synthetic air-permeable barriers over the perforations or louvers such as disclosed in U.S. Pat. No. 5,238,450. However, this system allows insect ingress through the perforations or louvers into the space between the perforations or louvers and the air-permeable barrier mat wherein they can nest and form insect colonies.
The prior art has also provided for ventilation by placing synthetic fiber matting constructed of randomly-aligned synthetic fibers which are joined by phenolic or latex binding agents and heat cured to provide an air-permeable mat placed over the opening of the roof ridge. Such system provides for preventing insect ingress through the roof ridge vent but does not prevent ingress by insects through the soffit vent system.
U.S. Pat. No. 5,328,406 discloses a fascia ventilator and drip edge comprising:
a panel having an upper and a lower section; the upper section being disposed on the roof structure, and the lower section attached to the vertical wall structure in a horizontally-spaced position; PA1 lip structure carried on the lower section; PA1 a baffle member engageable with the lip structure, the baffle member having a pair of spaced baffle walls extending parallel to the lower section and providing passage means for directing air flow upwardly, PA1 vertical side walls; and PA1 sloping roof extending outwardly and beyond the vertical side walls and forming eaves over said vertical side walls. The eaves comprising a horizontal soffit and a vertical face plate. A plurality of vents is provided in the horizontal soffit which on the inside, the side facing the attic, is covered by a strip of mat of randomly oriented synthetic fibers. The strip of mat conforms to the inside of the soffit, leaving no gap therebetween so that if insects pass through the vents in the soffit, they would not be able to nest between the soffit and the strip of mat. PA1 vertical side walls; and PA1 sloping roof extending outwardly and beyond the vertical side walls and forming eaves over said vertical side walls. PA1 a panel of air-impermeable material having an upper section and a lower section. Preferably, the two sections are integral, however, they may be separate sections joined together by hinges or other means. The upper sections runs parallel with, and underneath, the sloping roof structure while the lower section runs parallel with the vertical side walls. At the junction of the two sections they form a bend of a generally U-shaped configuration the peak of which faces the outside and serves as a drip edge to direct moisture, such as rain and snow, flowing down the sloping roof away from the vertical side walls. Typically, the drip edge drops the moisture into a gutter attached to the lower section of the air-impermeable panel positioned just under the drip edge.
whereby air can pass upwardly between the lower section and the vertical wall structure toward an opening above the vertical wall structure.
The invention does not appear to provide prevention of insect ingress into the attic space.
U.S. Pat. No. 5,560,157 discloses a fascia vent for ventilation of vapors from the attic of a building structure. The fascia is secured to the outer end of the roof rafters and at least one portion of the fascia is spaced from the outer ends of the rafters. An air permeable and resilient strip is interposed between the fascia and the outer ends of the rafters to provide for the flow of vapor therebetween and into the attic.
The air-permeable and resilient strip is not placed on, or supported by, a louver or baffle to hold the strip in place, but it is secured to the end of the rafters by adhesives or nails.
Although the resilient strip prevents ingress to insects, it restricts the flow of outside air into the attic since outside air can only enter into the strip through the gap between the fascia and the strip or through the narrow underside of the strip. The fascia board positioned over the strip also tends to either compress the strip against the rafters, or provide inadequate support for the strip if a wider gap is maintained between the fascia and the strip.
The object of the present invention is to provide an improved soffit ventilation system which together with an appropriate roof ridge vent solves the problems described above.